by Michael Shade, IQS Editor
It’s a consequence of the fact that I’ve never participated in a trade or craft that I see the words “tube bending machine” and feel a bit nonplussed. Tube bending machine? Why not just make the tubes bent instead of making them straight and then bending them? I realize that this is the kind of question that someone who has never taken a shop class would ask (shop wasn’t even offered at my high school, as far as I know). Maybe there are machines that exist that can produce bent tubes right from the start. But the fact that there are so many different kinds of tube forming machines on the market, added to the fact that the market for these machines seems quite large, indicates to me that tube fabrication and formation is a counter-intuitively complicated process.
Bent tubing used in an engine component.
A moment ago, I stumbled upon an online forum for discussion about amateur aircraft building. After getting over the shock of the fact that there may be an amateur aircraft somewhere in the air above me at a given moment, I noted some of the creative ways that the members get a hold of the various parts they need in order to build their dopey little planes. In some cases, they make their own parts. For example, one of the threads featured a few suggestions about DIY tube bending methods; apparently, amateur aircraft building involves the use of tubes in large quantities. One user’s post featured an image of a man who had cut a hemisphere out of thick plywood, nailed the hemisphere to another piece of plywood and then bent a tube over the first hemisphere until it took the wood’s shape. I could almost hear the struggling and grunting as I looked at the picture, and I imagined a large pile of discarded, deformed attempts just outside of the frame.
I was also struck by the fact that this guy was going to put his little home-made tube into his home-made aircraft and then try to fly it. Gravity doesn’t care how professional or amateurish your plane is. In order to become airborne and stay there, an airplane has to meet certain, very specific conditions of configuration and performance. The faith that these hobbyists have in their craftsmanship is astounding to me. Now, considering what can go wrong just because of a simple miscalculation in the shape of a tube, I fully appreciate the importance of tube forming machines and the vast need for them. They are a far cry from the Rube Goldberg systems that hobbyists cobble together in order to make the parts they need.
It’s not just bending machines, either. Tube cutting machines ensure that the length of a tube is precise, tube notchers embed the surfaces of tubes with precise shapes at precise intervals and swaging machines impart diametric changes into tubing to precise tolerances. The key word here is “precision.” Precision is the difference between hobby and trade. If I knew that Boeing was making planes with parts that some guy bent over some plywood in his garage, I would be less than enthusiastic about booking flights with airlines that use their aircraft. Instead, it’s much more likely that Boeing contracts the production of its aircraft tubes to companies that use tube forming machines. In addition to being more precise, they’re capable of working with materials that would be difficult for amateurs to work. Output is another key factor here; an automated tube forming line is likely to have a production rate that exponentially exceeds an amateur’s.
Let’s also consider the variable of composition. Tube forming doesn’t involve only metal tubing. Many of the kinds of tubes that industry and commerce need access to are made of polymers, all varieties of which feature different physical properties. For this reason, certain varieties of tube formation machines aren’t suitable for certain varieties of tubing materials. The kind of equipment used to cut PVC tubing, for example, might not be appropriate for tubing composed of a different kind of plastic.
Much like in any other industrial context, tube forming machines give customers access to something they need: high-quality, precision parts in large volumes with short lead times. In light of the fact that most large business expect all of those qualities from the products they order, the value of tube forming machines is unambiguously clear.